*There are three main categories of anesthesia, each having many forms and uses. They are local, regional and general:
The anesthetic drug is usually injected into the tissue to numb just the specific location of your body requiring minor surgery, for example, on the hand or foot.
Your anesthesiologist makes an injection near a cluster of nerves to numb the area of your body that requires surgery. You might be awake, or you may be given something to help you relax, sometimes called a sedative. There are several kinds of regional anesthesia. Two of the most frequently used are spinal and epidural anesthesia, which are produced by injections made with great exactness in the appropriate areas of the back. They are frequently preferred for childbirth and prostate surgery.
You are unconscious and have no awareness or other sensations. There are a number of general anesthetic drugs. Some are gases or vapors inhaled through a breathing mask or tube and others are medications introduced through a vein. During anesthesia, you are carefully monitored, controlled and treated by your anesthesiologist. A breathing tube may be inserted through your mouth and frequently into the windpipe to maintain proper breathing during this period. The length and level of anesthesia is calculated and constantly adjusted with great precision. At the conclusion of surgery, your anesthesiologist will reverse the process and you will regain awareness in the recovery room. *From the American Society of Anesthesiologists